In 1991, S. Iijima (Nature, vol. 354 pp. 56-58) reported growth of multi-wall coaxial nanotubes, containing 2-50 layers with radial separations of about 0.34 nm, using an arc discharge evaporation method similar to that used for Fullerene synthesis. The nanotubes originally observed by Iijima were formed on the negative voltage end of a carbon electrode and were plentiful in some regions and sparse in other regions. Since that time, other workers have developed other discharge means for controlled deposition of graphitic carbon. However, it is not straightforward to discriminate between, and control the growth of, a single wall nanotube (“SWNT”), a multi-wall nanotube (“MWNT”) and/or a nanofiber (“NF”).
The SWNTs, MWNTs and NFs potentially have many applications that rely upon the large mechanical strength and/or large electrical conductivity associated with these structures, if the patterning of such structures can be controlled. Some workers have used liquid catalysts to initiate growth of some carbon nanotubes, but patterning of a finely detailed array of such structures is difficult or impossible using a liquid.
What is needed is a system and procedure that allows one to controllably deposit a catalyst pattern to initiate growth of an array of SWNTs, an array of MWNTs, or an array of NFs, with firm control of shapes and dimensions of the regions where such carbon nanotubes are grown.